A mechanician that I know told me that the damage on the inside lip (extra rubber inside, not the bead) of the tire like the image below is normal and often happens when mounting/unmounting tires each year.
The tire is fine (holding air correctly) and the guy who told me that is not the one who did this damage.
Question is: Does this kind of damage is normal or it should not really happen with modern equipment and a good technician?
Note that this is run-flat tires, which are more stiff.
Thanks